Ответ: 1. David must have taken your books by mistake. 2. They shouldn’t have parked outside the police station. 3. Liz can’t have met Harry before. 4. You needn’t have cleaned the floor. 5. Heather might not have left yet. 6. They can’t have eaten all the food. It’s not possible! 7. Jack should have arrived half an hour ago. 8. Perhaps Pam and Tom might have decided not to come. 9. It must have been the cat that took the fish from the table! 10. It must have been a waste of time worrying, after all!